Adapters are frequently used in centrifuges to reduce bore size in rotors, particularly when specimens are confined in sealed labware. Specimens which are toxic, corrosive, sensitive to the ambient environment or accurately measured are often contained in sealed cuvettes, flasks or the like to preserve specimen integrity. When there is a need to centrifuge such specimens, researchers prefer to maintain the specimens in the same container. However, often the available centrifuge rotors have bores which are too large for such sealed containers.
Although bore reduction adapters are known, labware failure is a concern because toxic or corrosive specimens which leak from the labware can infiltrate the environment of the centrifuge location. Labware failure and labware seal failure can be expected in centrifuges because as the speed of use increases, so does seal pressure. Specimens may then, by centripetal force, attack further seals and possibly escape from the centrifuge, especially where the centrifuge chamber pressure is low, i.e. below ambient, say one-quarter atmosphere and below. Some laboratories require double and even triple seals to prevent accidental contamination of the laboratory environment.
Seals for centrifuge rotors which use centrifugal force to force a cap or plug against a container are known. For example, see U.S. Pat. Nos. 5,127,895 to R. Pawlovich; 5,395,001 to P. Moore; 5,361,922 to P. Moore et al.; 4,304,356 to S. Chulay et al.; 4,290,550 to S. Chulay et al.; 4,080,175 to S. Chulay et al.; and 4,076,170 to S. Chulay et al., all assigned to the assignee of the present invention. In some of these patents, deformable o-rings are used as part of the seal mechanism. Tapered surfaces, annular ridges and annular grooves are all employed, as in U.S. Pat. No. 5,395,001 to achieve a sealed sample.
An object of the invention was to devise a rotor adapter which incorporates good seals, which provides protection in the event of labware failure, which is easy to insert into, and remove from, a rotor and which seals easily.